What are the nhra/ihra requirements for running a mid 9 sec. 1/4 mile? thanks

 

My 04 NHRA rule book says 7.50-9.99 or faster than 135 MPH need a cage welded to the frame. Hope that helps, Good luck to ya

 

In NHRA to run mid 9s you deffinatly need 10 point, and I believe to go 8.50 and quicker you now need the diagonal door bars also. And last I knew you needed chassis certs if you wanted to compete with a 9.99 or quicker car. In IHRA you can go 9.0 with an uncerted 6 point roll bar, you do need an IHRA licence to run 9s though.

 

For NHRA, to run between 8.50 and 9.99 or if you exceed 135mph you need a full roll cage. There is not requirment for a 10 point or 12 point, etc, it is a design and layout that must be followed, not a point requirment. If you plan on running between 8.49 to 7.50 in the 1/4 you will need to have a cage that is SFI 25.5 legal. Which is alot more involved than a basic cage. Any roll cage must be certified by a NHRA Chassis Inspector to be legal. You will also need to have a window net installed anytime that a roll cage is required.

 

ok thanks guys. Where can i find something that shows the design that must be followed for nhra? Might as well build the cage right the first time.

 

You need a NHRA rule book. Go to www.NHRA.com and join. You will get a rule book with your membership. Good Luck.

Coach

 

A rulebook is very helpful and should be followed to a tee but isn't the best help for how to put one in. Your best bet is to go to local track and start checking some cars out. Lots of racers can be very helpful. Just like engines, you see that roll bars and chassis work varies quite a bit for car to car. Just make sure it's done right the first time and that the job is guaranteed to pass certification. If you're doing it yourself, take your time and ask lots of questions. I did my own and wound up doing them as a side job for several years now.

 

If you want the REAL spec's that NHRA abides by... go to http://www.sfifoundation.com/ and order the roll cage specification book for the cage/roll bar you are looking to build.

You can also contact a LS1tech sponsor (Dan @ Wolfe) who has already done all the leg work and sells a kit for the camaro's

 

alright sounds good. I will prob. do it myself since i have a tig welder and a pipe bender. Why is there so much of a difference between nhra and ihra's cage rules?

 

each sanctioning body can pretty much make it's own set of rules. IHRA used to be 11.50 for a 5-point bar, then when NHRA changed their's from 11.99 to 11.50, IHRA did the opposite (11.50 to 11.99). As mentioned above, check out your options before getting any work done. I'd also plan what tracks you may run at and/or what classes, and see what requirements/rules they have.

Derek

 

ok, i got the nhra book but have 2 questions. If you have a diagonal door bar, nhra requires it to be 1 5/8 0.083 cm. If you already have a 1 3/4 0.095 since that is bigger than required is that OK? Also i ddid not see anything that stated a requirement of any sort of bar going through the front firewall and tieing into the engine bay front frame rails. Am i missing something? Everyone else seems to have these bars. sorry about all the questions.

 

1-bigger tubing is always better for a bar/cage, so they shouldn't hassle you on that.
2-a roll cage doesn't require through firewall bars (at least based on cars I've seen done up running as fast as 8.50's). If you need pictures of what to look for, send me a pm and I'll send ya some.

Derek

 

ok, i was pretty sure you did not have to have the through firewall bars but i saw alot of people that had them so i wanted to double check. I have looked at about 5 or 6 cars but i'll send you a pm. More pictures can never hurt. thanks for the help

 

the different sizes is for different materials, the larger size is req for mild steel, smaller is good with chromoly. also to run 9.99 or quicker you must have a NHRA competion license. the bars going thru the firewall to the front just help stiffen the chassis.

 

the difference in sizes is the tubing size in different areas of the cage. The diagonals for the door bars are required to be 1 5/8" x .083 CM. I alrady have 1 3/4 CM door bars from the old 6 point roll bar so i wanted to reuse them and was just checking to make sure it was ok to run a larger bar than they state.

 

I like to keep it simple. Everything I bend is 1 3/4". It's the only die I have also. LOL It's nice to be able to use the smaller, lighter stuff where you can though. Don't forget the lower door bar if your car is without a full frame from the factory. It's mandatory on subframe cars.

 

Yeah got the lower door bar in. I just had the diagonal bars left over from a 6 point cage so i wanted to notch them and reuse them insted of bending up more stock CM isn't too cheap and i have to order it everytime i need any b/c no one around me has it in their shops.